Spirit duplicating systems are still largely used in this country and abroad by many institutions, particularly schools. The use of toxic, volatile, and flammable liquids for transfer fluids in these systems have been a limitation since their inception. The transfer fluid is a solvent which dampens the copy sheet enabling the extraction of some of the dye from the master to make an image on the copy. Transfer fluids typically are either comprised of 90% ethanol, or methanol, with the remainder a composite of water and/or cellosolve, a material which improves the solubility of the dye material on the master so as to produce a result of better transferred images on the copies made.
As noted, a small percentage of water has been used in order to reduce the cost of current transfer fluids. However, the percentage of water is limited to under 10%, to avoid resultant paper curl.
As identified, the methanol, or ethanol systems are extremely flammable and toxic. This results, in significant storage and disposal problems.
Further, people who have to work routinely with these types of systems, and especially those employing a methanol transfer fluid, expose themselves to the potential for serious eye damage. People working with the ethanol base systems on a regular basis can be adversely affected as well.
Recently, it has been identified that certain of the cellosolve additive materials have carcinogenic side effects which have discouraged their continuing use. Alternative materials to the cellosolve have been found. However, these have resulted in an unpleasant odor, as well as headache and nausea.
The use of water heretofore has been avoided because of the significant paper curl which results when the paper is submitted to the wetting of the transfer fluid. With percentages in excess of the amounts used in the methanol or ethanol systems, the paper curl became so bad and occurred so quickly, that routine paper jams occurred in the duplicating machines, after a copy or two. This has been attributed to the relatively quick expansion of the copy paper side receiving the transfer fluid containing the water, in comparison to the opposite side.
Further, in order for the water base systems to be pursued, a system would have to be devised which would avoid corrosive effects on the machine parts. Also, due to the nature of the transfer system in some of these machines, i.e., a form of wicking system, any attempts to use water in the past would have required a highly pure form of water, with little or no dissolved minerals which could crystallize and cake-up the wicking system.
It is therefore a primary object of this invention to provide transfer fluid which does not result in curling of the copy paper.
It is another object of this invention to provide a water based, transfer fluid which does not result in a curling of the copy paper.
It is another object of this invention to provide a transfer fluid which is not toxic.
It is still another object of this invention to provide a transfer fluid which is odorless.
It is yet another object of this invention to provide a transfer fluid which is anticorrosive.